1. Field of the Invention
The present invention relates to a thermal image transfer recording medium capable cf producing highly reliable transferred images having improved friction and scratch resistance and heat resistance, and chemical resistance.
2. Discussion of Background
There are conventionally known thermal image transfer recording media having an ink layer comprising an epoxy resin with a softening point of 60.degree. to 110.degree. C. and a coloring agent, as disclosed in Japanese Laid-Open Patent Application 60-59159. Such conventional thermal image transfer recording media can yield transferred images on a sheet of plain paper, a plastic film and a sheet of metallic foil in one coloring operation, and further, the thus transferred images have good preservability and wear-resisting properties.
However, since the ink layer of the above-mentioned conventional thermal image transfer recording medium comprises the epoxy resin having a softening point of 60.degree. to 110.degree. C., as previously mentioned, the thermal image transfer recording medium is poor in the friction-resisting properties at high temperatures. More specifically, the transferred images become blurred and illegible when rubbed with corrugated cardboard at high temperatures, for instance, at 70.degree. C.
Further, images transferred on a recording sheet from the above-mentioned conventional recording medium containing epoxy resin do not have so much sufficient lubricating properties that they readily lift off the recording sheet when brought into contact with hard materials such as metal edge or a nail.
In addition, the conventional thermal image transfer recording medium has the shortcoming that the transferred images obtained are vulnerable to chemicals, for example, industrial alcohol, engine oil, brake oil, kerosene, car wax, toluene, xylene, and "Perclene" for dry-cleaning.